Final answer:
The structural elements in blood vessel walls are the inner endothelium, middle smooth muscle layer, and outer connective tissue layer. These elements facilitate exchange of substances, regulate blood flow and pressure, and provide structural support and flexibility.
Step-by-step explanation:
The structural elements found in blood vessel walls serve different functions. These elements consist of three tunics or layers: the inner endothelium, the middle smooth muscle layer, and the outer connective tissue layer. The inner endothelium is a smooth, single layer of cells that facilitate the exchange of substances between the blood and surrounding tissues. The middle smooth muscle layer provides the ability to constrict or dilate the blood vessels, allowing for regulation of blood flow and blood pressure. The outer connective tissue layer provides structural support and flexibility to the blood vessel.